Electric condenser



Patented June 7, 1927.

UNITED STATES -WALTER R. G. BAKER, F SCHIENECTADY,

NEW YORK, ASSIGNOR TO GENERAL ELEC'- TRIC COMPANY, .A CORPORATION-OF NEW YORK.

ELECTRIC CONDENSER.

Application ill'ed February This invention relates to electric condensers adapted for use on high voltage circuits, and its object is to improve the construction of certain types of condenser which have previously been built for high voltage use, such, for example, as the type of condenser in which a metal casing encloses the condenser plates and constitutes one terminal while the other terminal is formed by a conductor 'which passes through. the

top of the casing. Fusible insulating material, such as paraffin, fills the space bev tween the condenser lplate and casing. Heretofore as manufactured it has been customary to form the topf of the casing of a slab of molded insulating material, such as 'bakelita I have have found, however', in operating such a condenser lat lhigh frequency that this cover deteriorates rapidly due tothe high dielectric hysteresis losses in -the material of which the cover is composed. In a short time the cover becomes blistered and the heat generated melts lthe filling of insulating material beneath the same and so practically destroys the utility of the condenser.

According yto my present invention, I avoid the 'defects above referred to, irst, by f0rm\ ing the insulation around the projecting terminal of material in which such high dielectric hystereses losses do not occur, and second, in forming the cover partly of metal which not only is free from such losses but in addition acts as a means for conducting heat laway from the surrounding parts.

Other objects and advantages will ap`- pear from the following description taken in' connection with the accompanying drawing, wherein Fig. 1 is a perspectlve view of t0 a condenser embodying my invention, and Fig. 2 is a-,central section of the same, showing certain parts in elevation, and others diagrammatically.

Referring to the drawing, 10 represents 5 a metal casing within Whichare located thek condenserselements 11. These areforned of sheets of conducting material separated by sheetsrof insulating material. .As shown, the elements are arranged in six groups coni@ nected in series.l Surrounding the condenser elements is 4 fusible insulating mai terial 12,!such as paraiin, which `practically fills the casing. Secured to the casing 10 by means of screws 13, the cover 14 which 7, 1921. Serial No. 442,942.

comprises a metal plate 15, provided at the 56 center with an opening 16. Extending across said opening and secured to the metal plate by means of screws 17 and a clamping ring 18, is a sheet 19 composed of insulating material which'has low dielectric hysteresis loss characteristics. As a material ,of this character, I prefer to use mica, which is well adapted for use in the form of a sheet, as illustrated. Porcelain, however, may be used if desired. Passing through the center of the insulating sheet is the terminal 20. This is formed of a screw threaded rod provided with a head 21. Terminal strips, indicated diagrammatically at 22, surround the rod and are tightly held ybetween the head of the rod `and .the sheet 19 by nuts 23 and 24. The opposite terminal of the condenseris connected to the casing as indicated at 25.

While I have shown the condenser sheets in a vertical position, it is apparent that they may he arranged horizontally if desired. In either case, suitable means may be provided for placing the sheets under the desired compression, but as this forms nopart of the present invention the same will not be further described.

What I claim as new and desire to secure by Letters Patent of the United States, is: 1. A device of the character y described' comprising condenser elements and a housing ktherefor containing fusible insulating materialin which said elements are embedded,said housing comprising a metallic casing connected with one terminal of said condenser elements,a removable metallic cover plate for said casing having `a central 'openingtherein secured to said casing, a mica sheet secured to said plate to coversa'id opening, anda terminal member connected with 95 the opposite terminal of said condenser elements and secured to said mica sheet centrally of said opening. f.

2.A device of the l'character described comprising condenser elements, a metallic receptacle for said elements electrically con` nected with one terminal of said condenser `element/s, fusible insulating material sur-- rounding said elements, a removable metallic cover plate for said receptacle having a central opening therein, a mica disk covering said opening, a ring clamping said mica disk to said cover plate and a terminal stud secured ,to said mica disk centrally thereof and-connected with the opposite terminal of said condenser elements.'y

3. A high potential condenser comprising a condenser unit enclosed in a container, one Wall of saidcontainer having a lrelatively large opening therein, a sheet mica diaphragm disposed dacross said o ening, a high -f tension terminal 4for said'con enser unit eX- tending through said diaphragm, said 'diaphragm being of sicient extent to provide a relatively large distance between said terminal and the periphery of the opening, and means for securing said terminal in position relative to said diaphragm.

4.`The combination of a container, an electrical condenser in said container, the container having a relatively large opening therein, a terminal and support therefor comprising an insulating mica diaphragm 00 disposed across said 0 ening.

In `Witness whereo I have hereunto set my hand this'th day of February 1921.

WALTER R. G. BAKER. 

